Steam generation

Abstract

A heat exchanger assembly, comprising: heat exchanger pipework which comprises a plurality of elongate tube elements which extend in spaced relation and a plurality of pipe end couplings which fluidly connect open ends of respective tube elements, wherein the pipe end couplings each comprise a main body part to which the open ends of the respective tube elements are fixed, and an enclosure part which is fixed to the main body part and provides a closed fluid connection between the open ends of the respective tube elements; and a plurality of fins which extend in spaced relation and optionally substantially orthogonally to the tube elements, wherein the fins each comprise a sheet element, optionally a single, continuous sheet element, which includes a plurality of apertures through which extend respective ones of the tube elements, and a plurality of fin coupling elements which are located within respective ones of the fin apertures to interface the tube elements to the sheet elements.

The invention claimed is: 
     
       1. A heat exchanger assembly, comprising:
 heat exchanger pipework which comprises a plurality of elongate tube elements which extend in spaced relation; and 
 a plurality of fins which extend in spaced relation, wherein the fins each comprise a sheet element which includes a plurality of apertures through which extend respective ones of the tube elements, and a plurality of fin coupling elements which are located within respective ones of the fin apertures to interface the tube elements to the sheet elements, wherein the fin coupling elements are fabricated separately of the sheet elements and each comprise a flange which extends through the respective fin aperture, and the fin coupling elements located within the fin apertures of one sheet element are separate of the fin coupling elements located within the fin apertures of other sheet elements, and wherein the fin apertures each include a first locator, and the fin coupling elements each include a second locator, which is configured to locate with the first locator in a respective one of the fin apertures, thereby locating the rotational position of the respective fin coupling element. 
 
     
     
       2. A heat exchanger assembly, comprising:
 heat exchanger pipework which comprises a plurality of elongate tube elements which extend in spaced relation and a plurality of pipe end couplings which fluidly connect open ends of respective tube elements, wherein the pipe end couplings each comprise a main body part to which the open ends of the respective tube elements are fixed, and an enclosure part which is fixed to the main body part and provides a closed fluid connection between the open ends of the respective tube sections; and 
 a plurality of fins which extend in spaced relation, wherein the fins each comprise a sheet element which includes a plurality of apertures through which extend respective ones of the tube elements, and a plurality of fin coupling elements which are located within respective ones of the fin apertures to interface the tube elements to the sheet elements. 
 
     
     
       3. The assembly of  claim 2 , wherein the main body part comprises a body, which includes a flange which encloses a surface, and first and second bores which extend to the surface and provide fluid communication thereto. 
     
     
       4. The assembly of  claim 3 , wherein the flange defines an annular seat to which the enclosure part is fixed. 
     
     
       5. The assembly of  claim 4 , wherein the flange defines an upstand, which extends around the seat, to which the enclosure part is fixed by an annular weld. 
     
     
       6. The assembly of  claim 5 , wherein the upstand includes an inwardly-inclined internal chamfer for receiving the weld. 
     
     
       7. The assembly of  claim 3 , wherein the bores each include at least one groove into which the open end of a respective one of the tube elements is expanded. 
     
     
       8. The assembly of  claim 4 , wherein the bores each terminate at an upstand which projects from the surface and to which the open end of the respective one of the tube elements is fixed by an annular weld. 
     
     
       9. The assembly of  claim 8 , wherein the upstand includes an inwardly-inclined internal chamfer, the open end of the respective tube element includes an outwardly-inclined annular chamfer, and the chamfers together define a channel for receiving the weld. 
     
     
       10. The assembly of  claim 3 , wherein the enclosure part includes an internal cavity which defines an arcuate surface having first and second bend radii, which are disposed opposite the bores in the main body part, thereby defining a 180 degree bend between the through bores. 
     
     
       11. The assembly of  claim 10 , wherein the enclosure part includes a flange, which extends around the internal cavity, to which the main body part is fixed by an annular weld. 
     
     
       12. The assembly of  claim 11 , wherein the flange of the enclosure part defines an outwardly-inclined external chamfer for receiving the weld. 
     
     
       13. The assembly of  claim 11 , wherein the flange defines an annular seat, which corresponds to an annular seat as defined by the flange of the main body part. 
     
     
       14. The assembly of  claim 2 , wherein the main body part and the enclosure part are formed of stainless steel. 
     
     
       15. The assembly of  claim 14 , wherein the main body part and the enclosure part are fabricated by casting. 
     
     
       16. The assembly of  claim 1 , wherein the sheet element has a thickness of at least about 1 mm. 
     
     
       17. A fin for a heat exchanger assembly, the fin comprising:
 a plurality of tube elements; 
 a sheet element which includes a plurality of apertures through which extend respective ones of the tube elements; and 
 a plurality of fin coupling elements which are fabricated separately of the sheet element and located within respective ones of the fin apertures to interface the tube elements to the sheet elements, wherein the fin coupling elements each comprise a body part which is thermally connected to the sheet element and includes an aperture through which extends a respective one of the tube elements, a flange which extends from the body part and through the respective fin aperture and is thermally connected to the respective tube element, and a plurality of projections which are disposed radially outwardly of the flange and located to one side of the fin coupling element, presenting a surface which acts to disrupt a gas flow to the one side of the fin coupling element, with the flange and the projections extending in opposite directions. 
 
     
     
       18. The assembly of  claim 1 , wherein the sheet elements are spaced by a spacing of at least 2 mm. 
     
     
       19. The assembly of  claim 1 , wherein the sheet elements are spaced by a spacing of at least 3 mm. 
     
     
       20. The assembly of  claim 1 , wherein the fin coupling elements each comprise a body part which is thermally connected to a respective one of the sheet elements and includes an aperture through which extends a respective one of the tube elements, and a flange which extends from the body part and through the respective fin aperture and is thermally connected to the respective tube element. 
     
     
       21. The assembly of  claim 20 , wherein the flange comprises a tubular section which is a close fit to an outer dimension of the tube elements. 
     
     
       22. The assembly of  claim 20 , wherein the flange has a length of at least 3 mm. 
     
     
       23. The assembly of  claim 20 , wherein the body part has the form of a flat, annular part. 
     
     
       24. The assembly of  claim 20 , wherein the fin coupling elements each further comprise one or more projections. 
     
     
       25. The assembly of  claim 24 , wherein the one or more projections are disposed radially outwardly of the flange. 
     
     
       26. The assembly of  claim 25 , wherein the one or more projections extend from an outer peripheral edge of the body part. 
     
     
       27. The assembly of  claim 25 , wherein the flange and the one or more projections extend in opposite directions. 
     
     
       28. The assembly of  claim 27 , wherein the one or more projections have a length which acts to space the adjacent sheet element. 
     
     
       29. The assembly of  claim 1 , wherein the fin coupling elements each comprise a plurality of projections, which are located to one side of the fin coupling element, and present a surface which acts to disrupt a gas flow to the one side of the fin coupling element. 
     
     
       30. The assembly of  claim 1 , wherein the fin coupling elements are coated at least partially with a brazing material, which allows for brazing of the fin coupling elements to the tube elements and the sheet elements. 
     
     
       31. The fin of  claim 17 , wherein the flange comprises a tubular section which is a close fit to an outer dimension of the tube elements. 
     
     
       32. The fin of  claim 17 , wherein the body part has the form of a flat, annular part. 
     
     
       33. The fin of  claim 17 , wherein the projections extend from an outer peripheral edge of the body part. 
     
     
       34. The fin of  claim 17 , wherein the projections have a length which acts to space the adjacent sheet element. 
     
     
       35. The fin of  claim 17 , wherein the fin coupling elements are coated at least partially with a brazing material.